At present, five components are used for a lithium-ion battery in the prior art, which comprises a battery cap plate, battery electrode terminal posts, insulating devices between the electrode terminal posts and the battery cap plate, sealing rings between the electrode terminal posts and the battery cap plate, and nuts. Connection mode of these components is as follows: the electrode terminal posts are provided through through holes of the battery cap plate, the sealing rings are provided for isolation sealing between the electrode terminal posts and the battery cap plate, the insulating devices are provided between the electrode terminal posts and the battery cap plate for insulation therebetween, the nuts are screwed on screw threads of the electrode terminal posts for fastening the sealing rings; as the screw threads are used for pre-fastening, the screw thread portions of the electrode terminal posts are cylindrical structure, such cylindrical structure will easily rotate when it is borne a torsion, thereby causing damage or fracture of tabs connected to the positive and negative electrode terminal posts, even causing short circuit due to contact with a metal battery case.